Motion conversion apparatus

ABSTRACT

A motion conversion apparatus (110) comprises a rodrack assembly (110) and a gearshaft member (150). The rodrack assembly (110) comprises a first gear connection member (120) and two guide members (140). The gearshaft member (150) comprises a second gear connection member (160) configured to engage with the first gear connection member (120), and a guiding surface arrangement (170) configured to contact the guide members (140). The rodrack assembly (110) is configured to provide rotation of the gearshaft member (150) about a rotational axis (A) by reciprocating linear motion of the rodrack assembly (110) along a first spatial dimension (D1) orthogonal to the rotational axis (A), and/or the gearshaft member (150) is configured to provide reciprocating linear motion of the rodrack assembly (110) along the first spatial dimension (D1) by rotational motion of the gearshaft member (150) about the rotational axis (A). The guiding surface arrangement (170) is configured to simultaneously contact each guide member (140) during at least a portion of the reciprocating linear motion of the rodrack assembly (110).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application pursuant to 35 U.S.C. § 371 of International Patent Application PCT/US2018/022672, filed on Mar. 15, 2018, and published as WO 2019/177613 on Sep. 19, 2019, which is incorporated herein by reference in its entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates to apparatuses for converting linear motion to rotational motion and vice versa.

BACKGROUND INFORMATION

Apparatuses for converting linear motion to rotational motion or rotational motion to linear motion are typically used in systems such as internal combustion engines, pumps and compressors, as well as various other applications. For example, internal combustion engines typically generate rotational motion by burning gasoline, oil, or other fuel with air to produce linear motion of pistons, and translating the linear motion of the pistons to rotational motion to rotate a power shaft.

A need exists for an apparatus providing more efficient linear-to-rotational motion conversion and/or rotational-to-linear motion conversion, and increased transfer of power during linear-to-rotational motion conversion.

Constant velocity engine designs and technologies are described in U.S. Pat. No. 8,327,819, the entire contents of which are incorporated herein by reference.

SUMMARY

A motion conversion apparatus is disclosed. The motion conversion apparatus comprises at least one rodrack assembly and a gearshaft member. The rodrack assembly comprises a first gear connection member and two guide members. The gearshaft member comprises a second gear connection member configured to engage with the first gear connection member, and a guiding surface arrangement configured to contact the guide members. The rodrack assembly is configured to provide rotation of the gearshaft member about a rotational axis by reciprocating linear motion of the rodrack assembly along a first spatial dimension orthogonal to the rotational axis, and/or the gearshaft member is configured to provide reciprocating linear motion of the rodrack assembly along the first spatial dimension by rotational motion of the gearshaft member about the rotational axis. The guiding surface arrangement is configured to simultaneously contact each guide member during at least a portion of the reciprocating linear motion of the rodrack assembly.

A gearshaft member for a motion conversion apparatus is disclosed. The gearshaft member comprises a second gear connection member and a guiding surface arrangement. The second gear connection member is configured to engage with a first gear connection member of a rodrack assembly. The guiding surface arrangement includes wall surfaces of an interrupted central periodic groove, and an outer surface of the gear shaft member. The gearshaft member further comprises a third gear engagement and a fourth gear engagement. The third gear engagement and the fourth gear engagement face in opposite directions and are disposed on opposite surfaces of the second gear connection member along a first diameter of the second gear connection member. The gearshaft member further comprises a fifth gear engagement and a sixth gear engagement. The fifth gear engagement and the sixth gear engagement face in opposite directions and are disposed on opposite surfaces of the second gear connection member along a second diameter of the second gear connection member. The third gear engagement and the fourth gear engagement are offset relative to the fifth gear engagement and the sixth gear engagement in the third spatial dimension, such that a first gear engagement of the first gear connection member is engageable with the third gear engagement and the fourth gear engagement, and a second gear engagement of the first gear connection member is engageable with the fifth gear engagement and the sixth gear engagement.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages disclosed herein will become more apparent from the following detailed description of exemplary embodiments when read in conjunction with the attached drawings.

FIG. 1 is a schematic partial illustration of an exemplary embodiment of a motion conversion apparatus.

FIG. 2A is a schematic partial illustration of an exemplary embodiment of a rodrack assembly.

FIG. 2B is a schematic partial exploded view of an exemplary embodiment of a rodrack assembly.

FIG. 3 is a schematic partial illustration of an exemplary embodiment of a gearshaft member.

FIGS. 4-7 are schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus during operation over four respective phases of a 90-degree counterclockwise rotation of the gearshaft member.

FIG. 8 is a schematic partial illustration of an exemplary embodiment of a motion conversion apparatus.

FIGS. 9-21 are schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus during twelve respective phases spanning 180 degrees of clockwise rotation of the gearshaft member.

FIG. 22 shows schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus including multiple rodrack assemblies and gearshaft members.

FIG. 23 shows schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus including multiple rodrack assemblies and gearshaft members.

DETAILED DESCRIPTION

FIG. 1 shows an exemplary embodiment of a motion conversion apparatus 100.

In an exemplary embodiment, the motion conversion apparatus 100 comprises at least one rodrack assembly 110 (also illustrated in FIGS. 2A-B) and a gearshaft member 150 (also illustrated in FIG. 3).

In an exemplary embodiment, the rodrack assembly 110 comprises a first gear connection member 120 and two guide members 140.

In an exemplary embodiment, the gearshaft member 150 comprises a second gear connection member 160 configured to engage with the first gear connection member 120, and a guiding surface arrangement 170 configured to contact the guide members 140.

In an exemplary embodiment, the rodrack assembly 110 is configured to provide rotation of the gearshaft member 150 about a rotational axis A by reciprocating linear motion of the rodrack assembly 110 along a first spatial dimension D1 orthogonal to the rotational axis A, and/or the gearshaft member 150 is configured to provide reciprocating linear motion of the rodrack assembly 110 along the first spatial dimension D1 by rotational motion of the gearshaft member 150 about the rotational axis A.

In an exemplary embodiment, the guiding surface arrangement 170 is configured to simultaneously contact each guide member 140 during at least a portion of the reciprocating linear motion of the rodrack assembly 110.

In an exemplary embodiment, the first gear connection member 120 is located between at least one pair of opposing pistons 130 along the first spatial dimension D1. The opposing pistons 130 are configured to reciprocate along the first spatial dimension D1.

In an exemplary embodiment, the opposing pistons 130 are configured such that two strokes of the opposing pistons 130 cause one revolution of the gearshaft member 150.

In an exemplary embodiment, the guiding surface arrangement 170 comprises wall surfaces 173 of an interrupted central periodic groove 172, and an outer surface 174 of the gear shaft member 150.

In an exemplary embodiment, each of the two guide members 140 includes two opposite ends which each protrude from opposite sides of the first gear connection member 120. As such, each protruding end of a guide member 140 can engage with a respective gearshaft member 150.

In an exemplary embodiment, the guide members 140 are located on the first gear connection member 120.

In an exemplary embodiment, the guide members 140 include two shafts.

In an exemplary embodiment, the guiding surface arrangement 170 comprises wall surfaces 173 of an interrupted central periodic groove 172, and the shafts are configured to travel within the periodic groove 172 during the reciprocating linear motion of the rodrack assembly 110.

In an exemplary embodiment, each shaft is configured to spin along a longitudinal axis thereof. For example, each shaft can be attached to their supporting structure by bearing engagements or other mechanisms for allowing rotation of the shaft.

FIG. 2B shows an exploded view of an exemplary embodiment of a rodrack assembly 110. The first gear connection member 120 of the rodrack assembly 110 includes two openings 142 which each receive bearings 141 and a guide member 140. An exemplary assembly method involves inserting a first bearing 141 on one side of an opening 142, inserting a guide member 140 from the other side of the opening 142, and inserting a second bearing 141 from that other side of the opening 142, in order to hold the guide member 140 within the opening 142. Once all bearings 141 are pressed in place, the guide members 140 are allowed to rotate with the desired amount of end play.

In an exemplary embodiment, the distance between the two guide members 140 can be about equal to the distance between an inner wall surface 173 of an interrupted central periodic groove 172 of the gearshaft member 150 and the opposite outer surface 174 of the gearshaft member 150. In another exemplary embodiment, the distance between the two guide members 140 can be smaller, to substantially reduce or eliminate the risk of play between the gearshaft member 150 and the guide members 140.

In exemplary embodiments, using an outer surface 174 in addition to the interrupted central periodic groove 172 provides for a smoother and more efficient reversing linear motion (i.e., a smoother and more efficient transition from leftward motion to rightward motion of the rodrack assembly 110 and vice versa). In exemplary embodiments, such arrangement can also provide some or all of the following advantages: (1) the guide members 140 can turn in a substantially constant and continuous rotational direction, thus minimizing inefficiencies that would arise if the rotations of the guide members 140 were to significantly slow down; (2) the load of a guide member 140 need not change side of contact in the central periodic groove 172 when the rodrack direction is reversed; (3) noise associated with the load change of the groove side (e.g., a click or clatter) can be reduced; (4) there is more than one point of contact between the guide members 140 and the gearshaft member 150 as the rodrack assembly 110 reverses direction, thus reducing a wear point; and (5) it can be possible to attain a preload of guide member bearings in the rodrack assembly 110 as the guide members 140 engage in the groove 172 and with the outer surface 174.

In an exemplary embodiment, the first gear connection member 120 includes a first gear engagement 122 and a second gear engagement 124. The first gear engagement 122 and the second gear engagement 124 are opposed to one another in a second spatial dimension D2 parallel to the rotational axis A, and are offset from one another in the second spatial dimension D2 and a third spatial dimension D3. The first, second and third spatial dimensions D1, D2, D3 are orthogonal to one another, as indicated in FIG. 1. The second gear connection member 160 is disposed between the first gear engagement 122 and the second gear engagement 124 in the second spatial dimension D2.

In an exemplary embodiment, the second gear connection member 160 includes third, fourth, fifth and sixth gear engagements 162, 164, 166, 168. The third gear engagement 162 and the fourth gear engagement 164 face in opposite directions and are disposed on opposite surfaces of the second gear connection member 160 along a first diameter of the second gear connection member 160. The fifth gear engagement 166 and the sixth gear engagement 168 face in opposite directions and are disposed on opposite surfaces of the second gear connection member 160 along a second diameter of the second gear connection member 160. The third gear engagement 162 and the fourth gear engagement 164 are offset relative to the fifth gear engagement 166 and the sixth gear engagement 168 in the third spatial dimension D3, such that the first gear engagement 122 is engageable with the third gear engagement 162 and the fourth gear engagement 164, and the second gear engagement 124 is engageable with the fifth gear engagement 166 and the sixth gear engagement 168.

In exemplary embodiments, the gear engagements can include one or more teeth, grooves, sprockets, and/or sprocket engagement rollers, and/or any other gear engagements known in the art.

In an exemplary embodiment, the second gear connection member 160 extends through the reciprocating rodrack assembly 110.

In an exemplary embodiment, the rodrack assembly 110 is configured to provide constant rotation of the gearshaft member 150 by the reciprocating linear motion of the rodrack assembly 110.

In an exemplary embodiment, the gearshaft member 150 includes a central hole extending through the second gear connection member 160.

In an exemplary embodiment, the second gear connection member 160 is located between the guide members 140.

In an exemplary embodiment, a gearshaft member 150 for a motion conversion apparatus 100 comprises a second gear connection member 160 and a guiding surface arrangement 170. The second gear connection member 160 is configured to engage with a first gear connection member 120 of a rodrack assembly 110. The guiding surface arrangement 170 includes an interrupted central periodic groove 172 and an outer surface 174 of the gear shaft member 150. The gearshaft member 150 further comprises a third gear engagement 162, a fourth gear engagement 164, a fifth gear engagement 166 and a sixth gear engagement 168. The third gear engagement 162 and the fourth gear engagement 164 face in opposite directions and are disposed on opposite surfaces of the second gear connection member 160 along a first diameter of the second gear connection member 160. The fifth gear engagement 166 and the sixth gear engagement 168 face in opposite directions and are disposed on opposite surfaces of the second gear connection member 160 along a second diameter of the second gear connection member 160. The third gear engagement 162 and the fourth gear engagement 164 are offset relative to the fifth gear engagement 166 and the sixth gear engagement 168 in the third spatial dimension D3, such that a first gear engagement 122 of the first gear connection member 120 is engageable with the third gear engagement 162 and the fourth gear engagement 164, and a second gear engagement 124 of the first gear connection member 120 is engageable with the fifth gear engagement 166 and the sixth gear engagement 168.

FIGS. 4-7 show an exemplary embodiment of a motion conversion apparatus 100 during operation over four respective phases of a 90-degree counterclockwise rotation of the gearshaft member. A 90-degree rotation can be defined from Top Dead Center (TDC) to Bottom Dead Center (BDC).

FIG. 4 shows an exemplary embodiment of a motion conversion apparatus 100 at a configuration defined herein as corresponding to 0 degrees of counterclockwise rotation of the gearshaft member 150 relative to the rodrack assembly 110. This phase is an example of TDC at the right end. Lobes 152 are located on the outside of each section of the interrupted central periodic groove 172, which includes groove wall surfaces 173. At this phase, one lobe 152 is associated with the section of the interrupted central periodic groove 172 that is diametrically opposed, to provide for synchronous movement of both surfaces. In exemplary embodiments, each guide member 140 can thus engage simultaneously with a corresponding surface of the gearshaft member 150.

FIG. 5 shows an exemplary embodiment of a motion conversion apparatus 100 at about 4 degrees of counterclockwise rotation of the gearshaft member 150 relative to the rodrack assembly 110. Both guide members 140 are engaged with corresponding surfaces of the gearshaft member 150, and the rodrack assembly 110 has moved to the left from TDC (illustrated in FIG. 4). In alternative illustrative embodiments, the movement from FIG. 4 to FIG. 5 can be accomplished by the gearshaft member 150 rotating to move the rodrack assembly 110, or alternatively the rodrack assembly 110 could be moved linearly to rotate the gearshaft member 150.

FIG. 6 shows an exemplary embodiment of a motion conversion apparatus 100 at about 14 degrees of counterclockwise rotation of the gearshaft member 150 relative to the rodrack assembly 110. Both guide members 140 remain engaged with corresponding surfaces of the gearshaft member 150, and the rodrack assembly 110 has continued to move to the left relative to TDC (illustrated in FIG. 4). At this phase, the gear engagement 162 of the gearshaft member 150 is partially engaged with the gear engagement 122 of the rodrack assembly 110. The opposite gear engagement 124 of the rodrack assembly 110 and the offset gear engagement 164 of the gearshaft member 150 pass each other without contact as a result of the parallel offset bottom rail of the rodrack assembly 110.

FIG. 7 shows an exemplary embodiment of a motion conversion apparatus 100 at about 24 degrees of counterclockwise rotation of the gearshaft member 150 relative to the rodrack assembly 110. The rodrack assembly 110 has continued to move to the left relative to TDC (illustrated in FIG. 4). At this phase, the gear engagement 162 of the gearshaft member 150 is more fully engaged with the gear engagement 122 of the rodrack assembly 110 than was the case in FIG. 6. Both guide members 140 release contact with their corresponding surfaces of the gearshaft member 150. The guide members 140 will be free from control of gearshaft member 150 surfaces until the continued gearshaft member 150 rotation and rodrack assembly 110 movement approach about 24-degrees before BDC. At this point a mirror image of the above-described motion between the gearshaft member 150 and the rodrack assembly 110 will begin, and the cycle will repeat in the same linear direction until reaching BDC.

FIG. 8 shows an exemplary embodiment of a motion conversion apparatus 100. Piston heads 131 are attached to the rodrack assembly 110 by link rods 132 and are configured to be linearly displaced within stationary cylinder sleeves 133. Linear bearings 111 are stationary and are configured to guide the linear motion of the rodrack assembly 110. Guide members 140 are mounted with bearings in the rodrack assembly 110 so as to rotate relative to the rodrack assembly 110. Surfaces 173, 174 of the gearshaft member 150 are positioned directly opposite each other and maintain a specific distance so as to keep the guide members 140 in contact until gear engagements of the gearshaft member 150 and the rodrack assembly 110 are engaged.

FIGS. 9-21 show an exemplary embodiment of a motion conversion apparatus 100 during twelve respective phases spanning 180 degrees of clockwise rotation of the gearshaft member.

Like FIG. 8, FIG. 9 shows an exemplary embodiment of a motion conversion apparatus 100 in a TDC configuration at about 0 degrees of rotation of the gearshaft member 150.

FIG. 10 shows an exemplary embodiment of a motion conversion apparatus 100 at about 15 degrees of rotation of the gearshaft member 150. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are beginning to engage at the top rail of the rodrack assembly 110. Movement of the rodrack assembly 110 to the right is controlled by guide members 140 contacting surfaces of the gearshaft member 150, and less so by the engaging gear engagements.

FIG. 11 shows an exemplary embodiment of a motion conversion apparatus 100 at about 20 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the top rail of the rodrack assembly 110 are more fully engaged. Movement of the rodrack assembly 110 to the right is controlled by guide members 140 contacting surfaces of the gearshaft member 150, as well as by the engaging gear engagements.

FIG. 12 shows an exemplary embodiment of a motion conversion apparatus 100 at about 45 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the top rail of the rodrack assembly 110 are even more fully engaged. Movement of the rodrack assembly 110 to the right is controlled by the engaging gear engagements. The guide members 140 are no longer engaged with the surfaces of the gearshaft member 150.

FIG. 13 shows an exemplary embodiment of a motion conversion apparatus 100 at about 70 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the top rail of the rodrack assembly 110 are still engaged. Movement of the rodrack assembly 110 to the right is controlled by guide members 140 beginning to contact surfaces of the gearshaft member 150, as well as by the engaging gear engagements.

FIG. 14 shows an exemplary embodiment of a motion conversion apparatus 100 at about 80 degrees of rotation of the gearshaft member 150. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are beginning to disengage at the top rail of the rodrack assembly 110. Movement of the rodrack assembly 110 to the right is controlled by guide members 140 contacting surfaces of the gearshaft member 150, and less so by the engaging gear engagements.

FIG. 15 shows an exemplary embodiment of a motion conversion apparatus 100 at about 90 degrees of rotation of the gearshaft member 150. The rodrack assembly 110 has moved to the right, and the motion conversion apparatus 100 is now at BDC on the left and TDC on the right. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are disengaged. Movement of the rodrack assembly 110 is controlled by guide members 140 contacting surfaces of the gearshaft member 150.

FIG. 16 shows an exemplary embodiment of a motion conversion apparatus 100 at about 105 degrees of rotation of the gearshaft member 150. The rodrack assembly 110 is now moving left. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are beginning to engage at the bottom rail of the rodrack assembly 110. Movement of the rodrack assembly 110 to the left is controlled by guide members 140 contacting surfaces of the gearshaft member 150, and less so by the engaging gear engagements.

FIG. 17 shows an exemplary embodiment of a motion conversion apparatus 100 at about 110 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the rail of the rodrack assembly 110 are more fully engaged. Movement of the rodrack assembly 110 to the left is controlled by guide members 140 contacting surfaces of the gearshaft member 150, as well as by the engaging gear engagements.

FIG. 18 shows an exemplary embodiment of a motion conversion apparatus 100 at about 135 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the bottom rail of the rodrack assembly 110 are even more fully engaged. Movement of the rodrack assembly 110 to the left is controlled by the engaging gear engagements. The guide members 140 are no longer engaged with the surfaces of the gearshaft member 150.

FIG. 19 shows an exemplary embodiment of a motion conversion apparatus 100 at about 160 degrees of rotation of the gearshaft member 150. The gear engagements of the gearshaft member 150 and the rodrack assembly 110 at the bottom rail of the rodrack assembly 110 are still engaged. Movement of the rodrack assembly 110 to the left is controlled by guide members 140 beginning to contact surfaces of the gearshaft member 150, as well as by the engaging gear engagements.

FIG. 20 shows an exemplary embodiment of a motion conversion apparatus 100 at about 170 degrees of rotation of the gearshaft member 150. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are beginning to disengage at the bottom rail of the rodrack assembly 110. Movement of the rodrack assembly 110 to the left is controlled by guide members 140 contacting surfaces of the gearshaft member 150, and less so by the engaging gear engagements.

FIG. 21 shows an exemplary embodiment of a motion conversion apparatus 100 at about 180 degrees of rotation of the gearshaft member 150. The rodrack assembly 110 has moved to the left, and the motion conversion apparatus 100 is now in a TDC configuration on the left and a BDC configuration on the right. Gear engagements of the gearshaft member 150 and the rodrack assembly 110 are disengaged. Movement of the rodrack assembly 110 is controlled by guide members 140 contacting surfaces of the gearshaft member 150.

FIG. 22 shows schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus 200 including multiple rodrack assemblies 110 and gearshaft members 150. The gearshaft members 150 are configured to rotate together, while the rodrack assemblies 110 can be configured to either linearly translate together or in opposite directions, depending on the offset configuration of their respective gear connection members relative to the offset configuration of the gear connection members of the corresponding gearshaft members 150. Because each rodrack assembly 110 is located between two gearshaft members 150, opposite protruding ends of a guide member 140 can engage with a respective gearshaft member 150.

FIG. 23 shows schematic partial illustrations of an exemplary embodiment of a motion conversion apparatus 300 including multiple rodrack assemblies 110 and gearshaft members 150.

In exemplary embodiments, the motion conversion apparatus 100 provides an efficient way to convert continuous rotary motion to linear motion and vice versa, and provides increased transfer of power during linear-to-rotational motion conversion compared to known systems.

In exemplary embodiments, the motion conversion apparatus 100 can form a part of an internal combustion engine assembly, a pump assembly, a compressor assembly, or any other device involving linear-to-rotational motion conversion or rotational-to-linear motion conversion. As such, in exemplary embodiments, an internal combustion engine assembly comprises the motion conversion apparatus 100 as described herein, a pump assembly comprises the motion conversion apparatus 100 as described herein, and a compressor assembly comprises the motion conversion apparatus 100 as described herein.

In exemplary embodiments, the internal combustion engine assembly, the pump assembly, the compressor assembly, or any device involving linear-to-rotational motion conversion or rotational-to-linear motion conversion can include any combinations of the above-described features.

It will be appreciated by those skilled in the art that the disclosure herein can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Moreover, those skilled in the art will appreciate that the various features described herein can be combined in any arbitrary combination. The presently disclosed embodiments are therefore considered in all respects to be exemplary and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein. 

What is claimed is:
 1. A motion conversion apparatus (100) comprising: at least one rodrack assembly (110) comprising a first gear connection member (120) and two guide members (140); and a gearshaft member (150) comprising a second gear connection member (160) configured to engage with the first gear connection member (120), and a guiding surface arrangement (170) configured to contact the two guide members (140), the at least one rodrack assembly (110) being configured to provide rotation of the gearshaft member (150) about a rotational axis (A) by reciprocating linear motion of the at least one rodrack assembly (110) along a first spatial dimension (D1) orthogonal to the rotational axis (A), and/or the gearshaft member (150) being configured to provide reciprocating linear motion of the at least one rodrack assembly (110) along the first spatial dimension (D1) by rotational motion of the gearshaft member (150) about the rotational axis (A), the guiding surface arrangement (170) being configured to simultaneously contact each of the two guide members (140) during at least a portion of the reciprocating linear motion of the at least one rodrack assembly (110), wherein the guiding surface arrangement (170) comprises wall surfaces (173) of an interrupted central periodic groove (172), and an outer surface (174) of the pear shaft member (150).
 2. The motion conversion apparatus (100) according to claim 1, wherein each of the two guide members (140) includes two opposite ends which each protrude from opposite sides of the first gear connection member (120).
 3. The motion conversion apparatus (100) according to claim 1, wherein the two guide members (140) are located on the first gear connection member (120).
 4. The motion conversion apparatus (100) according to claim 1, wherein the two guide members (140) include two shafts.
 5. The motion conversion apparatus (100) according to claim 4, wherein the guiding surface arrangement (170) comprises wall surfaces (173) of an interrupted central periodic groove (172), and the two shafts are configured to travel within the periodic groove (172) during the reciprocating linear motion of the at least one rodrack assembly (110).
 6. The motion conversion apparatus (100) according to claim 4, wherein each of the two shafts is configured to spin along a longitudinal axis thereof.
 7. The motion conversion apparatus (100) according to claim 1, wherein the first gear connection member (120) includes a first gear engagement (122) and a second gear engagement (124), the first gear engagement (122) and the second gear engagement (124) being opposed to one another in a second spatial dimension (D2) parallel to the rotational axis (A), and being offset from one another in the second spatial dimension (D2) and a third spatial dimension (D3), the first, second and third spatial dimensions (D1, D2, D3) being orthogonal to one another, the second gear connection member (160) being disposed between the first gear engagement (122) and the second gear engagement (124) in the second spatial dimension (D2).
 8. The motion conversion apparatus (100) according to claim 7, wherein the second gear connection member (160) includes: a third gear engagement (162) and a fourth gear engagement (164), the third gear engagement (162) and the fourth gear engagement (164) facing in opposite directions and being disposed on opposite surfaces of the second gear connection member (160) along a first diameter of the second gear connection member (160); and a fifth gear engagement (166) and a sixth gear engagement (168), the fifth gear engagement (166) and the sixth gear engagement (168) facing in opposite directions and being disposed on opposite surfaces of the second gear connection member (160) along a second diameter of the second gear connection member (160), wherein the third gear engagement (162) and the fourth gear engagement (164) are offset relative to the fifth gear engagement (166) and the sixth gear engagement (168) in the third spatial dimension (D3), such that the first gear engagement (122) is engageable with the third gear engagement (162) and the fourth gear engagement (164), and the second gear engagement (124) is engageable with the fifth gear engagement (166) and the sixth gear engagement (168).
 9. The motion conversion apparatus (100) according to claim 1, wherein the second gear connection member (160) extends through the at least one reciprocating rodrack assembly (110).
 10. The motion conversion apparatus (100) according to claim 1, wherein the at least one rodrack assembly (110) is configured to provide constant rotation of the gearshaft member (150) by the reciprocating linear motion of the at least one rodrack assembly (110).
 11. The motion conversion apparatus (100) according to claim 1, wherein the gearshaft member (150) includes a central hole extending through the second gear connection member (160).
 12. The motion conversion apparatus (100) according to claim 1, wherein the first gear connection member (120) is located between at least one pair of opposing pistons (130) along the first spatial dimension (D1), the opposing pistons (130) being configured to reciprocate along the first spatial dimension (D1).
 13. The motion conversion apparatus (100) according to claim 12, wherein the opposing pistons (130) are configured such that two strokes of the opposing pistons (130) cause one revolution of the gearshaft member (150).
 14. The motion conversion apparatus (100) according to claim 1, wherein the second gear connection member (160) is located between the two guide members (140).
 15. A gearshaft member (150) for a motion conversion apparatus (100), the gearshaft member (150) comprising: a second gear connection member (160) and a guiding surface arrangement (170), the second gear connection member (160) being configured to engage with a first gear connection member (120) of a rodrack assembly (110), the guiding surface arrangement (170) including an interrupted central periodic groove (172) and an outer surface (174) of the gear shaft member (150), a third gear engagement (162) and a fourth gear engagement (164), the third gear engagement (162) and the fourth gear engagement (164) facing in opposite directions and being disposed on opposite surfaces of the second gear connection member (160) along a first diameter of the second gear connection member (160); and a fifth gear engagement (166) and a sixth gear engagement (168), the fifth gear engagement (166) and the sixth gear engagement (168) facing in opposite directions and being disposed on opposite surfaces of the second gear connection member (160) along a second diameter of the second gear connection member (160), wherein the third gear engagement (162) and the fourth gear engagement (164) are offset relative to the fifth gear engagement (166) and the sixth gear engagement (168) in the third spatial dimension (D3), such that a first gear engagement (122) of the first gear connection member (120) is engageable with the third gear engagement (162) and the fourth gear engagement (164), and a second gear engagement (124) of the first gear connection member (120) is engageable with the fifth gear engagement (166) and the sixth gear engagement (168).
 16. An internal combustion engine assembly comprising: the motion conversion apparatus (100) according to claim
 1. 17. A pump assembly comprising: the motion conversion apparatus (100) according to claim
 1. 18. A compressor assembly comprising: the motion conversion apparatus (100) according to claim
 1. 